褐菖鲉的视觉器官发育

The Development of Visual Organ in Sebastiscus marmoratus

为研究褐菖鲉(Sebastiscusmarmoratus)视觉器官发育与生态习性及摄食行为之间的关系,用组织学方法对人工培育条件下的褐菖鲉仔、稚鱼的视觉器官发育特征进行了详细观察。结果表明,褐菖鲉为卵胎生鱼类,其视觉器官的分化速度较一般鱼类快,从母体产出时,仔鱼视网膜神经细胞层和原始晶状体已形成;1日龄仔鱼的视网膜分化为6层,晶状体出现纤维化,直径约72μm,仔鱼开始具有一定趋光性;2日龄仔鱼视网膜分化完成,可见10层结构,巩膜出现,与仔鱼开口摄食相适应,游泳能力增强;5～7日龄晶状体直径达99μm,晶状囊形成;17日龄,仔鱼角膜结构分化完成,脉络膜趋于完善;37日龄稚鱼的视觉器官各部分已经发育完全。

To explore the relationship between the development of visual organ, ecological habits and the feeding behaviors of Sebastiscus marmoratus, histological methods were employed to study the developmental characteristics of visual organ in larvae and juvenile fish. The results showed that the differentiation rate of S. marmoratus was faster than that of other species. As an ovoviviparous fish, the retinal nerve cell layer and the original lens were already formed at birth. The 1-day-old larvae of S. marmoratus already had phototaxis. The retina of 1-day-old larvae differentiated into six layers, the lens became fibrosis, and the diameter was about 72 μm. The retina differentiated into ten layers and the sclera appeared to adapt to its feeding behavior at 2-day-old. In this period, the swimming ability was enhanced. The crystalline capsule was formed during 5﹣7 days and its diameter of lens was about 99 μm. Table 1 describes S. marmoratus′ structural characteristics and development speed of the retina, and Fig. 1 shows the development characteristics of visual organ in S. marmoratus 1﹣5 days old larvae. On the 17 th day, the corneal structure was differentiated and the choroid was fully developed. Until 37 days, the vision organ was completely developed in the juveniles. Fig. 2 shows microscope observation of the development characteristics of visual organ in S. marmoratus 5﹣26 days old larvae and young fish, and Table 2 reflects the relationship between the retinal formation time and behavior development in different fishes.